1. Field of the Invention
This invention pertains to a multi-digit roller meter for volume or current measurement whose indicator reading can be electronically read by means of an encoder that is activated for each reading.
2. Discussion of the Background of the Invention and Material Information
Volume measuring devices or instruments for gas and water, as well as electric meters for the measurement of energy flowing therethrough, are known, in which the measured volume or the measured energy is transferred via a step down mechanism, associated with the measuring instrument, to a mechanical roller meter. The roller meter shows, since its last zero setting or resetting, the volume that has passed therethrough since its resetting. In order to determine the usage during a specified period, the setting of the roller meter is read at the beginning and end of this period. A preferred embodiment of the roller meter consists of having an axis upon which the indicator wheels or cipher rolls are rotatably journalled and upon whose circumference the numerals 0 to 9 are placed, as well as having a second axis, with rotatable shift pinion wheels, in such a way that each time the lower value indicator wheel, in the last tenth of a revolution, via its allocated shift pinion wheel, shifts the next higher value wheel one tenth of a revolution. A typical roller meter for a water flow measuring instrument is set forth in prior art French Patent Publication 2.199.115. Depending upon the construction of the measuring instrument, in order to achieve extensive measuring range while maintaining good measuring accuracy, it is important that the required moment of torsion or moment of rotating is held to the lowest possible value.
Prior art U.S. Pat. No. 3,732,404 teaches a solution for the electronic readout of a meter in which the continuous turning movement of the indicator wheels is translated into a snapping motion. It must be assured that the spring or other mechanism, that is utilized for the snapping motion, obtains sufficient energy in order to advance the entire wheel or roller package one setting, for example from 19999 to 20000.
European Patent Publication No. EP 202722 B1 teaches a solution which permits the electronic readout of a meter of the needle type via the use of mechanical contacts without snap motion. Naturally it is also possible to utilize a meter of the needle type in synchronization with a meter having indicator wheels or cipher rolls.